The Curtiss XP-42, a conversion of a P-36A Mohawk airframe, was employed as a testbed at Wright Field, Ohio, beginning in March 1939 to determine whether stream-lining could reduce drag in a radial-powered fighter and make it competitive with more advanced fighters employing inline engines. This concept was seen as an alternative to adapting the P-36A airframe to an inline powerplant, as had been done with the prototype P-40 Warhawk. Delivered to the Army in March 1939, the XP-42 was powered by a 783kW Pratt & Whitney R-1830-31 Twin Wasp radial enclosed by a bullet-shaped, sheet-metal cowling extended forward to culminate in a large, pointed spinner. An airscoop below the spinner provided cooling air, while smaller intakes above the engine provided air to the carburettor. It was immediately clear that this sleek, long-nosed configuration offered none of the advantages of the inline engine employed not only by the P-40 but also by such types as the Messerschmitt Bf 109 and North American Mustang. The aerodynamic nose shape provided almost no reduction in drag, and cooling problems proved almost insurmountable. While the XP-42 was marginally faster than the open-cowl P-36A, its performance did not compare favourably with the P-40 or with other, newer fighters of the immediate pre-war period.

A variety of nose configurations was tried on the XP-42, altering its fuselage length with each change, but none vindicated the enclosed radial engine and Curtiss's production facilities, in the event, were taken up with the inline-powered P-40. When hostilities began, the XP-42 had been ruled out as a possible production aircraft but continued to aid in research. In 1942, the XP-42 tested an all-flying stabilizer, similar to the stabilator found on modern jets. The XP-42 had begun flying in natural metal finish and was camouflaged during one of its minor rebuilds. The airframe, which contributed knowledge to designers and engineers, was eventually taken out of service as other wartime priorities beckoned. Curtiss would continue to explore new fighter ideas with XP-46, XP-60 and XF-87, but the company's predominant role in the fighter field was fast becoming history.

Specification

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WEIGHTS

Take-off weight

2839 kg

6259 lb

Empty weight

2185 kg

4817 lb

DIMENSIONS

Wingspan

11.38 m

37 ft 4 in

Length

9.32 m

31 ft 7 in

Height

3.66 m

12 ft 0 in

Wing area

21.83 m2

234.98 sq ft

PERFORMANCE

Max. speed

506 km/h

314 mph

Ceiling

9450 m

31000 ft

Range

966 km

600 miles

Comments

Tom, 06.05.2014

Sturm what are you talking about? At that point in US Air Corp history performance requirements were issued to all interested companies and designs were openly competed. A lot of attempts were made to improve the breed of several designs. The p-36 design went to the P-40, P-42, P-46 and P-60, just for one example. There were several variations on the P-60. None of them were improvements over existing designs, so why bother with them. The North American P-51 was not even asked for but offered to the British as a better design than the P-40. First an acceptable design did not really come into its own until the Allison engine was replaced by the Rolls Royce Merlin. So there is little evidence of favoritism. Had there been then Curtiss with its long line of fighters from the 1920's and 30's would have remained the favorite, clearly they did not. Certainly nothing, absolutely nothing in comparison to the NAZI's.Leo, what do you mean in your question? The US Army Air Corp tried just about anything that came along. Just look at the P-45, -46, -48, -49, -50. And there are several more. No matter how you cut it the best designs were the more conservative designs.

Sturm, 04.06.2010

I couldn't really say. U.S. military has historically stuck to conservative designs (of course there are exceptions). I wouldn't doubt there were some political reasons behind backing some manufacturers over others (I'm not saying this is the case here) such as Nazi Germany's Messerschmitt bias and the USSR's MiG bias.

leo rudnicki, 08.04.2009

like the Vought p66 and FW190, the ducted spinner proved inefficient, but like the final FW190 layout, a properly designed close-cowled engine/spinner combination proved effective, raising the speed to 340mph, fast enough to run away from a Zero. What did the U.S. military have against aerodynamicists?